A Comparative Study of Neat Epoxy Coating and NanoZrO2/Epoxy Coating for Corrosion Protection on Carbon Steel

2014 ◽  
Vol 599-601 ◽  
pp. 3-6
Author(s):  
Xia Zhao ◽  
Shuan Liu ◽  
Bao Rong Hou

nanoZrO2 was modified by styrene coupling grafting method and then used as an additive to improve the protective performance of epoxy coating. Two kinds of coatings, neat epoxy coating and nanoZrO2/epoxy coating, were prepared and applied on Q235 carbon steel plates. The plates were submitted to salt spray chamber and seawater immersion for 1000 hours to evaluate the corrosion protection performance for these two kinds of coatings. Tafel polarization curves and electrochemical impedance spectroscopy (EIS) were determined to analyze the corrosion behavior of coating/metal system. Scanning electron microscopy (SEM) and photographs were carried out for morphology analysis of two kinds of coatings under different conditions. Results showed a superior stability and efficient corrosion protection by nanoZrO2 /epoxy coating. The modified nanoZrO2 could inhibit the penetration of corrosive media and then improve the corrosion protection of the epoxy coating on carbon steel.

2021 ◽  
Author(s):  
Huan-Yan Xu ◽  
Lu Zhang ◽  
Yun-Fei Wang ◽  
Xu Han

Abstract In order to improve the anticorrosive performance of waterborne epoxy (WEP) coating, small amounts of polyaniline (PANI) were blended under ultrasonic irradiation to obtain PANI/WEP composite coatings with high dispersibility of PANI particles. The PANI/WEP composite coatings were characterized by Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). Their adhesive force level and hardness grade were tested based on the Chinese National Standard GB/T9286-1998 and GB/T6739-1996, respectively. These results indicated that, compared to the pristine WEP coating, the addition of PANI with suitable content could completely fill the micropores or microcracks and remarkably improve the hardness grade of composite coatings. The electrochemical impedance spectra (EIS) and Tafel polarization curves revealed that the addition of PANI not only could increase the impedance arc, but also could increase the impedance modulus at low frequency. Then, the salt spray tests were employed to observe the anticorrosive performance of PANI/WEP composite coatings. Finally, the enhanced anticorrosive mechanism of WEP coating by the addition of small amounts of PANI was proposed and discussed. The addition of PANI with suitable content could play an important role of physical and chemical barriers to improve the anticorrosive performance of waterborne epoxy coating.


2018 ◽  
Vol 56 (2) ◽  
pp. 165
Author(s):  
Anh Son Nguyen ◽  
Thuy Duong Nguyen ◽  
Thu Thuy Thai ◽  
Thi Xuan Hang To

The present work investigated the corrosion protection performance of ions Ce3+ activated-cerium(IV) oxides nanoparticles for carbon steel in a NaCl solution. Ceria nanoparticles were synthesized by homogeneous precipitation in ethanol/water mixed solvent. The obtained CeO2 nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The corrosion inhibition action of the activated nanoparticles by cerium(III) ions on carbon steel in NaCl solution was evaluated by electrochemical measurements (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization). Then, the effect of cerium salt activated-CeO2 on the protection properties of poly-vinyl-butyral (PVB) coating deposited onto carbon steel plate was studied by salt spray test. The obtained results showed that the salt activated-nanoparticles are anodic corrosion inhibitors. The presence of Ce3+ activated CeO2 in the coating improved the barrier properties and corrosion protection performance of the PVB coating. No swellings of coating were observed after 48 hours of exposure in salt spray chamber.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Jacob Ress ◽  
Ulises Martin ◽  
Juan Bosch ◽  
David M. Bastidas

The protection of mild steel by modified epoxy coating containing colophony microencapsulated corrosion inhibitors was investigated in this study. The corrosion behavior of these epoxy coatings containing colophony microcapsules was studied by electrochemical analysis using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The microcapsule coating showed decreased corrosion current densities of 2.75 × 10−8 and 3.21 × 10−8 A/cm2 along with corrosion potential values of 0.349 and 0.392 VSCE for simulated concrete pore solution and deionized water with 3.5 wt.% NaCl, respectively, indicating improved corrosion protection in both alkaline and neutral pH. Electrochemical impedance spectroscopy analysis also showed charge transfer resistance values over one order of magnitude higher than the control sample, corroborating the electrochemical corrosion potential and current density testing results. Overall, the use of colophony microcapsules showed improved corrosion protection in simulated concrete pore solution and DI water solutions containing chloride ions.


2019 ◽  
Vol 66 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Walid Belmaghraoui ◽  
Aimad Mazkour ◽  
Hicham Harhar ◽  
Mourad Harir ◽  
Souad El Hajjaji

Purpose This study aims to investigate the corrosion inhibition effect of extracted oil from Ziziphus lotus fruit on corrosion of C38 carbon steel in 5.5 M H3PO4 solution using potentiodynamic polarization and impedance techniques. Design/methodology/approach Oil composition was determined using gas chromatography, and the results showed that oleic and palmitic acids present approximately 84.0 per cent of its total chemical content. Electrochemical impedance spectroscopy (EIS) data were analyzed by adapting it to a well-developed electric circuit model. The inhibition efficiency of Z. lotus oil was calculated and compared using Tafel polarization and EIS. Findings Accordingly, the oil extract was found to act as an anodic type inhibitor. Furthermore, inhibition efficiency of Z. lotus oil extract increase with oil concentrations and achieve approximately 70.5 per cent at 3 g/L solution of Z. lotus oil. Originality/value The results obtained from different tested methods were in line, and the oil was able to reduce significantly the kinetics of the corrosion process of C38 carbon steel.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1578 ◽  
Author(s):  
Haijuan Yang ◽  
Qiufeng Mo ◽  
Weizhou Li ◽  
Fengmei Gu

An organic coating is commonly used to protect metal from corrosion, but it is prone to failure due to microcracks generated by internal stress and external mechanical action. The self-healing and self-lubricating achieved in the coating is novel, which allows an extension of life by providing resistance to damage and repair after damage. In this study, a new approach to microencapsulating bifunctional linseed oil with polyurethane shell by interfacial polymerization. Moreover, the self-healing and self-lubricating coatings with different concentrations of microcapsules were developed. The well-dispersed microcapsules showed a regular spherical morphology with an average diameter of ~64.9 μm and a core content of 74.0 wt.%. The results of the salt spray test demonstrated that coatings containing microcapsules still possess anticorrosion, which is improved with the increase of microcapsules content, after being scratched. The results of electrochemical impedance spectroscopy showed a |Z|f=0.01Hz value of 104 Ω·cm2 for pure epoxy coating after being immersed for 3 days, whereas the coating with 20 wt.% microcapsules was the highest, 1010 Ω·cm2. The results of friction wear showed that the tribological performance of the coating was enhanced greatly as microcapsule concentration reached 10 wt.% or more, which showed a 86.8% or more reduction in the friction coefficient compared to the pure epoxy coating. These results indicated that the coatings containing microcapsules exhibited excellent self-healing and self-lubricating properties, which are positively correlated with microcapsules content.


2020 ◽  
Vol 25 (4) ◽  

The study is examines the assessment of the corrosion-protective properties of zinc-rich coating based on water sodium silicate (ZRC) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl reference electrode in 3 M solution of KCl, auxiliary electrode – Pt (8x8 mm) and working electrodes for determination potential (Ecorr) and impedance measurement, salt spray test method and natural teszzt method at Dam Bay Marine Research Station, Nha Trang, Khanh Hoa, Viet Nam. ZSC can provide good cathodic protection when zinc content is 70% by weight or more. ZSC with a mixing ratio of High Modulus Liquid Sodium Glass / Zinc Powde : 25/75 by weight (working title – TTL-VN) has good corrosion protection after 16 cycles salt spray test and after 18 months natural test in seawater. The paint film has basic parameters as adhesion – 4,41 MPa, flexural strength – 2 mm, pendulum hardness – 0,62 conventional units and initial coating potentia l – 0,96 V Ag/AgCl.


2020 ◽  
Vol 147 ◽  
pp. 105864 ◽  
Author(s):  
Mahboobeh Attaei ◽  
Lénia M. Calado ◽  
Yegor Morozov ◽  
Maryna G. Taryba ◽  
R.A. Shakoor ◽  
...  

2019 ◽  
Vol 66 (5) ◽  
pp. 595-602
Author(s):  
Zhifeng Lin ◽  
Likun Xu ◽  
Xiangbo Li ◽  
Li Wang ◽  
Weimin Guo ◽  
...  

Purpose The purpose of this paper is to examine the performance of a fastener composite coating system, sherardized (SD) coating/zinc-aluminum (ZA) coating whether it has good performance in marine environment. Design/methodology/approach In this paper, SD coating was fabricated on fastener surface by solid-diffusion method. ZA coating was fabricated by thermal sintering method. Corrosion behaviours of the composite coating were investigated with potentiodynamic polarization curves, open circuit potential and electrochemical impedance spectroscopy methods. Findings Neutral salt spray (NSS) and deep sea exposure tests revealed that the composite coating had excellent corrosion resistance. Polarization curve tests showed that corrosion current density of the sample with composite coating was significantly decreased, indicating an effective corrosion protection of the composite coating. OCP measurement of the sample in NaCl solution demonstrated that the composite coating had the best cathodic protection effect. The good corrosion resistance of the composite coating was obtained by the synergy of SD and ZA coating. Practical implications SD/ZA coating can be used in marine environment to prolong the life of carbon steel fastener. Social implications SD/ZA composite coating can reduce the risk and accident caused by failed fastener, avoid huge economic losses. Originality/value A new kind of composite coating was explored to protect the carbon steel fastener in marine environment. And the composite coating has the long-term anti-corrosion performance both in simulated and marine environment test.


2019 ◽  
Vol 66 (2) ◽  
pp. 188-194
Author(s):  
Yingjun Zhang ◽  
Xue-Jun Cui ◽  
Yawei Shao ◽  
Yanqiu Wang ◽  
Guozhe Meng ◽  
...  

PurposeThis paper aims to prepare a residual rust epoxy coating by adding different quantities of phytic acid (PA) on the surface of the rusty steel and investigate the corrosion protection of PA and its action mechanisms.Design/methodology/approachA residual rust epoxy coating by adding different quantities of PA was prepared on the surface of the rusty steel. The influence of PA on the corrosion resistance of epoxy-coated rusty steel was investigated by means of electrochemical impedance spectroscopy and adhesion testing.FindingsResults indicated that PA can substantially improve the corrosion resistance of epoxy-coated rusty steel. This improvement is due to the reaction of PA with residual rust and generation of new compounds with protection properties and increased adhesive strength effects on the coating/metal interface. The coating showed better protection performance when 2 per cent PA was added.Originality/valueConsidering the structure of the active groups, PA has strong chelating capability with many metal ions and can form stable complex compounds on the surface of a metal substrate, thereby improving corrosion resistance. In recent years, PA has been reported to be useful in the conversion of coatings or as green corrosion inhibitor. To the best of the authors’ knowledge, few studies have reported the use of PA as a rust converter or residual rust coating. The present work aims to improve the corrosion resistance of residual rust epoxy coating by adding PA.


Sign in / Sign up

Export Citation Format

Share Document